Many of us have a dire need for a Necro class, so I thought I'd throw my idea in the ring. Take aspects from the current four classes and make them necromantic.
Ardent Flame has the Firey Grip chain-pulling, so make that a boney hand on a purple beam and it becomes Death Embrace under the Cold Touch tree.
An undead summoning tree - kill a foe, and with a spell you can make a skeleton/zombie rise out of them. (I've seen NPCs do something like that) Ultimate for that tree? Summon a Bone Colossus!
And the healing side skill tree - area spells that heal allies while damaging foes BUT (with a certain passive) when an enemy dies they can get resurrected to fight for you. Maybe.
I really just want to go around as a combat-necromancer, killing things with a sword and using their corpse as fodder. Oh well.